Traditionally, Internet routing is achieved through shortest path protocols that base their decision on the number of hops or administrative metrics. The path computation algorithms belong either to the distance vector or link state families. Distance vector protocols have been widely used on the Internet since the ARPANET and remain in use today. The protocols of the Distance Vector family are used by routers to exchange routing information with their neighbours and to select the shortest paths to all destinations within the network using the Bellman-Ford algorithm, such as in the routing information protocol (RIP) (Malkin, 1998).
